A new study says that women infected with the parasite, toxoplasma gondii, may be more likely to attempt suicide.
The parasite, Toxoplasma gondii, which is common among cats, was found to cause changes in the human brain and even cause mental illness.
University of Maryland researchers looked at the health records of 45,000 Danish women over 14 years.
They found that those diagnosed with the parasite were more than 50 percent more likely to commit suicide than other patients, reported Fox News.
They also found the women at risk for more violent forms of suicide like using knives or guns.
Researchers warned that the study does not definitively link the suicides with the parasite.
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"We can't say with certainty that T. gondii caused the women to try to kill themselves, but we did find a predictive association between the infection and suicide attempts later in life that warrants additional studies," said lead author Teodor T. Postolache, of the University of Maryland, according to Red Orbit.
"We plan to continue our research into this possible connection."
Yet, according to Time, the link between "toxo" and suicide held, even when other factors such as socioeconomic status, were accounted for.
The parasite is most common among cats but lives in many warm-blooded animals, including birds.
It is believed that nearly one in three people are infected with the virus, with most laying dormant in the brain with no symptoms.
The virus spreads most often through cat feces, which may find their way into the human body through uncooked vegetables or meat or from litter boxes, said the Globe and Mail.
The study was published in the Archives of General Psychiatry.